package com.example.springcloud.service;

import cn.hutool.core.util.IdUtil;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.PathVariable;

import java.util.concurrent.TimeUnit;


@Service
public class PaymentService {
    /**
     * 正常访问，肯定OK
     *
     * @param id
     * @return
     */
    public String paymentInfo_OK(Integer id) {
        return "线程池:  " + Thread.currentThread().getName() + "  paymentInfo_OK,id:  " + id + "\t" + "O(∩_∩)O哈哈~";
    }

    @HystrixCommand(fallbackMethod = "paymentInfo_TimeOutHandler", commandProperties = {
            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")
    })
    public String paymentInfo_TimeOut(Integer id) {
        //int age = 10/0;
        try {
            TimeUnit.MILLISECONDS.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return "线程池:  " + Thread.currentThread().getName() + " id:  " + id + "\t" + "O(∩_∩)O哈哈~" + "  耗时(秒): ";
    }

    public String paymentInfo_TimeOutHandler(Integer id) {
        return "线程池:  " + Thread.currentThread().getName() + "  8001系统繁忙或者运行报错，请稍后再试,id:  " + id + "\t" + "o(╥﹏╥)o";
    }

    /**
     *  上故意制造两个异常：
     *    1  int age = 10/0; 计算异常
     *    2  我们能接受3秒钟，它运行5秒钟，超时异常。
     *    当前服务不可用了，做服务降级，兜底的方案都是paymentInfo_TimeOutHandler
     */


    //=====服务熔断=========//

    /**
     * 熔断机制概述
         * 熔断机制是应对雪崩效应的一种微服务链路保护机制。当扇出链路的某个微服务出错不可用或者响应时间太长时，
         * 会进行服务的降级，进而熔断该节点微服务的调用，快速返回错误的响应信息。
         * 当检测到该节点微服务调用响应正常后，恢复调用链路。
     * 在Spring Cloud框架里，熔断机制通过Hystrix实现。Hystrix会监控微服务间调用的状况，
     * 当失败的调用到一定阈值，缺省是5秒内20次调用失败，就会启动熔断机制。熔断机制的注解是@HystrixCommand。
     * @param id
     * @return
     */
    @HystrixCommand(fallbackMethod = "paymentCircuitBreaker_fallback", commandProperties = {
            @HystrixProperty(name = "circuitBreaker.enabled", value = "true"),// 是否开启断路器
            @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "10"),// 请求次数
            @HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds", value = "10000"), // 时间窗口期
            @HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "60"),// 失败率达到多少后跳闸
    })
    public String paymentCircuitBreaker(@PathVariable("id") Integer id) {
        if (id < 0) {
            throw new RuntimeException("******id 不能负数");
        }
        String serialNumber = IdUtil.simpleUUID();

        return Thread.currentThread().getName() + "\t" + "调用成功，流水号: " + serialNumber;
    }

    public String paymentCircuitBreaker_fallback(@PathVariable("id") Integer id) {
        return "id 不能负数，请稍后再试，/(ㄒoㄒ)/~~   id: " + id;
    }

}
